We illustrate the effective couplings by exemplifying CoFeB wires of width \(w=150\)  nm and thickness \(d=20\)  nm on top of a Ni film of thickness \(s=5\)  nm. With \(\mu _0\tilde{M}_s=0.6\)  T for Ni [1]} and \(\mu _0M_s=1.6\)  T [2]} for CoFeB of stiffness \(\alpha _{\rm ex}=8\times 10^{-13}~{\rm cm}^2\)  [3]}, [4]}, we plot the direction dependence of the coupling constants \(\Gamma _{L,R}\)  on the applied magnetic field of strength \(\mu _0H_{\rm app}=0.1\)  T in Fig. REF . With these parameters, the frequency of the Kittel modes of CoFeB wire is \(\omega _{\rm K}=60\)  GHz [5]}.
The coupling is perfect chiral when the magnetizations of wire and film are parallel (\(\Gamma _R\ne 0\)  but \(\Gamma _L=0\) ) or anti-parallel (\(\Gamma _L\ne 0\)  but \(\Gamma _R=0\) ). The chirality vanishes at two critical angles \(\phi _c=\lbrace 0.4\pi ,1.6\pi \rbrace \) . Thereby, the system allows to simulate rich physics from with perfect to in the absence of chirality.
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